The present invention relates to an apparatus and concomitant method for image production, e.g., a movie film or motion video. More particularly, this invention relates to a method and apparatus that produces images from digitally stored dynamic background sets.
Creating a story line in an image based system (e.g., movie film, video tape, and the like) is usually a very expensive undertaking involving moving large numbers of cast and crew to a set location, and/or building a very expensive studio set. Namely, the story line can be broadly defined as having xe2x80x9cforeground activitiesxe2x80x9d and xe2x80x9cbackground activitiesxe2x80x9d. The foreground activities may comprise interaction between characters, e.g., chatting, walking, running, and the like, whereas the background activities may comprise activities found behind the characters, e.g., activities of a busy city street with moving vehicles, activities of background people in a market place or restaurant, landscape view with moving tree branches, clouds, water and the like. While the foreground activities will change from one image production to another, the background set or activities may be used repeatedly for different image productions, e.g., the skylines and famous landmarks of well-known cities such as New York City, Paris, and London are subjects of numerous image productions. To physically transport an entire cast and supporting personnel and equipment to such an xe2x80x9con locationxe2x80x9d site is extremely costly and time consuming.
Although compositing live foreground activities with a static stored background is currently available, e.g., compositing a weather forecaster standing before a blue background with a stored image of a map, unfortunately, such compositing technique is only appropriate for a static background such as a weather map, where the locations of the relevant objects are fixed and well known by the weather forecaster.
If a xe2x80x9cdynamic backgroundxe2x80x9d, i.e., a background scene with motion and activities, is required, then the foreground activities must be filmed or captured before a blue background, where the composite image production is then assembled at a later time. Unfortunately, due to the complex background motion and/or activities, e.g., a windy scene along a riverbank, the filming of the foreground activities must be carefully choreographed and meticulously executed to maintain realism in the final image production. Thus, actors and actresses must perform complex actions before a blank blue background with only rough estimates of their spatial placement relative to the spatial placement of activities in the stored background. Additionally, important differences in conditions between the stored backgrounds and the on-site location such as lighting conditions and camera angles are also difficult parameters to account for at the time of the on-site location filming.
These criticalities present great challenges to actors, film crew and directors, since the success of the live filming may not be easily ascertained until the stored background activities are composited with the newly filmed foreground activities at a later time. Namely, powerful image processing systems are generally only available at an image production facility and is not readily available on-location. Since the overall composite image is not available at the time of filming of the foreground activities, substantial live refilming or modification at the production facility may then be required if error is found, thereby increasing the overall cost and time of image production. If guidance concerning the composite image can be immediately provided on location, the filming of the foreground activities can be simplified, e.g., refilming the scene at a slight different angle, changing the lighting on the set and the like.
Therefore, there is a need in the art for a method and apparatus that is capable of providing a composite of the stored dynamic background activities with the newly filmed or captured live foreground activities, thereby providing a real-time and on-site guide to actors and directors and greater artistic freedom.
In one embodiment of the present invention, a method and apparatus is disclosed that provides a composite of the stored dynamic background activities (i.e., a background image sequence) with the newly filmed or captured live foreground activities (i.e., a foreground image sequence), thereby providing a real-time and on-site guide to actors and directors. Specifically, ancillary data representative of the scene condition are captured for both the background image sequence and the foreground image sequence. The scene condition includes but is not limited to the camera parameters and the lighting condition at the time of capturing the image sequence. The ancillary information can be captured and disposed directly on the image sequence itself, thereby allowing an image processing system to quickly render the composite image sequence. To further alleviate the computational burden, the compositing operation is performed in low resolution in one embodiment.
Using the ancillary data, the present image production system is able to quickly and effectively provide a composite image sequence by compositing the background image sequence with the foreground image sequence in real time, e.g., at the time of filming the foreground image sequence. The composite image sequence can then be distributed to a viewfinder on a camera and to a monitor at the studio environment, thereby providing a very useful on-site guide to actors, film crew and directors.